Add Htu31d and refactor Htu21d to Htux1d

Source/Meadow.Foundation.Peripherals/Sensors.Atmospheric.Htu21d/Driver/Htu21d.Enums.cs

@@ -4,21 +4,6 @@ namespace Meadow.Foundation.Sensors.Atmospheric
 {
     public partial class Htu21d
     {
-        /// <summary>
-        /// Valid addresses for the sensor.
-        /// </summary>
-        public enum Addresses : byte
-        {
-            /// <summary>
-            /// Bus address 0x40
-            /// </summary>
-            Address_0x40 = 0x40,
-            /// <summary>
-            /// Default bus address
-            /// </summary>
-            Default = Address_0x40
-        }
-
         private const byte SOFT_RESET = 0xFE;
 
         private const byte TEMPERATURE_MEASURE_NOHOLD = 0xF3;
@@ -43,10 +28,5 @@ public enum SensorResolution : byte
             TEMP13_HUM10 = 0x80,
             TEMP11_HUM11 = 0x81,
         }
-
-        private enum Register : byte
-        {
-
-        }
     }
 }

Source/Meadow.Foundation.Peripherals/Sensors.Atmospheric.Htu2xd/Driver/Drivers/Htu21d.Enums.cs

@@ -0,0 +1,45 @@
+namespace Meadow.Foundation.Sensors.Atmospheric
+{
+    public partial class Htu21d
+    {
+        enum Registers : byte
+        {
+            SOFT_RESET = 0xFE,
+
+            TEMPERATURE_MEASURE_NOHOLD = 0xF3,
+            HUMDITY_MEASURE_NOHOLD = 0xF5,
+
+            TEMPERATURE_MEASURE_HOLD = 0xE3,
+            HUMDITY_MEASURE_HOLD = 0xE5,
+            TEMPERATURE_MEASURE_PREVIOUS = 0xE0,
+
+            WRITE_USER_REGISTER = 0xE6,
+            READ_USER_REGISTER = 0xE7,
+            READ_HEATER_REGISTER = 0x11,
+            WRITE_HEATER_REGISTER = 0x51,
+        }
+
+        /// <summary>
+        /// Resolution of sensor data
+        /// </summary>
+        public enum SensorResolution : byte
+        {
+            /// <summary>
+            /// 14 bit temperature, 12 bit humidity 
+            /// </summary>
+            TEMP14_HUM12 = 0x00,
+            /// <summary>
+            /// 12 bit temperature, 8 bit humidity 
+            /// </summary>
+            TEMP12_HUM8 = 0x01,
+            /// <summary>
+            /// 13 bit temperature, 10 bit humidity 
+            /// </summary>
+            TEMP13_HUM10 = 0x80,
+            /// <summary>
+            /// 11 bit temperature, 11 bit humidity 
+            /// </summary>
+            TEMP11_HUM11 = 0x81,
+        }
+    }
+}

Source/Meadow.Foundation.Peripherals/Sensors.Atmospheric.Htu2xd/Driver/Drivers/Htu21d.cs

@@ -0,0 +1,116 @@
+using Meadow.Hardware;
+using Meadow.Units;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using HU = Meadow.Units.RelativeHumidity.UnitType;
+
+namespace Meadow.Foundation.Sensors.Atmospheric
+{
+    /// <summary>
+    /// Provide access to the Htu21d(f)
+    /// temperature and humidity sensors
+    /// </summary>
+    public partial class Htu21d : Htux1dBase
+    {
+        /// <summary>
+        /// Firmware revision of the sensor.
+        /// </summary>
+        public byte FirmwareRevision { get; private set; }
+
+        /// <summary>
+        /// Create a new Htu21d temperature and humidity sensor
+        /// </summary>
+        /// <param name="address">Sensor address (default to 0x40)</param>
+        /// <param name="i2cBus">I2CBus (default to 100 KHz)</param>
+        /// <param name="updateInterval">Update interval, defaults to 1 sec if null</param>
+        public Htu21d(II2cBus i2cBus, byte address = (byte)Addresses.Default, TimeSpan? updateInterval = null)
+            : base(i2cBus, address, updateInterval)
+        {
+            Initialize();
+        }
+
+        /// <summary>
+        /// Initialize HTU21D
+        /// </summary>
+        protected void Initialize ()
+        {
+            Peripheral?.Write((byte)Registers.SOFT_RESET);
+
+			Thread.Sleep(100);
+
+            SetResolution(SensorResolution.TEMP11_HUM11);
+        }
+
+        protected override async Task<(Units.Temperature? Temperature, RelativeHumidity? Humidity)> ReadSensor()
+        {
+            (Units.Temperature Temperature, RelativeHumidity Humidity) conditions;
+
+            return await Task.Run(() => 
+            {
+                // humidity
+                Peripheral?.Write((byte)Registers.HUMDITY_MEASURE_NOHOLD);
+                Thread.Sleep(20); // Maximum conversion time is 12ms (page 5 of the datasheet)
+
+                Peripheral?.Read(ReadBuffer.Span[0..2]);// 2 data bytes plus a checksum (we ignore the checksum here)
+                var humidityReading = (ushort)((ReadBuffer.Span[0] << 8) + ReadBuffer.Span[1]);
+                var humidity = (125 * (float)humidityReading / 65536) - 6;
+                humidity = Math.Clamp(humidity, 0, 100);
+                conditions.Humidity = new RelativeHumidity(humidity, HU.Percent);
+
+                // temperature
+                Peripheral?.Write((byte)Registers.TEMPERATURE_MEASURE_NOHOLD);
+                Thread.Sleep(20); // Maximum conversion time is 12ms (page 5 of the datasheet)
+
+                Peripheral?.Read(ReadBuffer.Span[0..2]);// 2 data bytes plus a checksum (we ignore the checksum here)
+                var temperatureReading = (short)((ReadBuffer.Span[0] << 8) + ReadBuffer.Span[1]);
+                conditions.Temperature = new Units.Temperature((float)(((175.72 * temperatureReading) / 65536) - 46.85), Units.Temperature.UnitType.Celsius);
+
+                return conditions;
+            });
+        }
+
+		/// <summary>
+		/// Turn the heater on or off
+        /// </summary>
+        /// <param name="heaterOn">Heater status, true = turn heater on, false = turn heater off.</param>
+        public void Heater(bool heaterOn)
+        {
+            if (Peripheral == null) return;
+
+            var register = Peripheral.ReadRegister((byte)Registers.READ_HEATER_REGISTER);
+            register &= 0xfd;
+
+            if (heaterOn)
+            {
+                register |= 0x02;
+            }
+            Peripheral.WriteRegister((byte)Registers.WRITE_HEATER_REGISTER, register);
+        }
+
+		//Set sensor resolution
+        /*******************************************************************************************/
+        //Sets the sensor resolution to one of four levels
+        //Page 12:
+        // 0/0 = 12bit RH, 14bit Temp
+        // 0/1 = 8bit RH, 12bit Temp
+        // 1/0 = 10bit RH, 13bit Temp
+        // 1/1 = 11bit RH, 11bit Temp
+        //Power on default is 0/0
+        void SetResolution(SensorResolution resolution)
+        {
+            if (Peripheral == null) return;
+
+            var register = Peripheral.ReadRegister((byte)Registers.READ_USER_REGISTER);
+
+            var res = (byte)resolution;
+
+            register &= 0x73; //Turn off the resolution bits
+            res &= 0x81; //Turn off all other bits but resolution bits
+            register |= res; //Mask in the requested resolution bits
+
+            //Request a write to user register
+            Peripheral.WriteRegister((byte)Registers.WRITE_USER_REGISTER, register); //Write the new resolution bits
+        }
+    }
+}